Mechanism for double printing with a possibility for barring second printing

ABSTRACT

A double-printing mechanism wherein a hammer drives a ribbon against a paper sheet on one side of a print wheel which is diametrically shiftable to bear against another ribbon and paper. The print wheel has a resiliently deflectable rim and means for shifting an anvil out of the way to exclude second printing.

United States Patent 1191 Stanchev et a1. 1 1 June 4, 1974 [541 MECHANISM FOR DOUBLE PRINTING 2,085,323 2/1936 Leash 101/376 WITH A POSSIBILITY F EARRING 2,818,801 2/1956 Hart et a1 c 101/1 10 3,169,474 6/1963 Howard 101/110 SECOND PRINTING 3,415,184 3/1967 Perucca 101/93 C [75] Inventors: Ivan Tenev Stanchev; Anton I Dimitrov Popov; Ivan Valbanov OTHER PUBLICATIONS of Sofia Bulgara IBM Technical Disclosure Bulletin, N. Rogers, Flex1' [73] Assignees Dso lzot, Sofia, Bulgaria ble Print Stick, Vol. 3, N0. 6, Nov. 1960, pg. 1. [22] Filed: May 1, 1972 Primary Examiner-J. Reed Fisher [2]] App! 249104 k Assistant Examiner-Paul J. Hirsch Attorney, Agent, or Firm-Karl F. Ross; Herbert [30] Foreign Application Priority Data u n Apr. 29, 1971 Bulgaria 16446 52 vs. C]. 101/90, 101/100 ABSTRACT III". Cl- A double printing mechanism wherein a hammer Flew Search 101/106, I drives a ribbon against a paper sheet on one side 01 11 101/95, 79,92 8171931376, 100; print wheel which is diametrically shiftablc to bear 197/1& 9. 55 against another ribbon and paper. The print wheel has a resiliently deflectable rim and means for shifting an 1 References Clted 1 anvil out of the way to exclude second printing. UNlTED STATES PATENTS 1,547.150 7/1923 Von Pein 101/90 x 6 Clam, 3 D'awmg F'gures PATENTEDJUH 41974 333141010 swam 2 0f 3 lla/ll,

MECHANISM FOR DOUBLE PRINTING WITH A POSSIBILITY FOR BARRING SECOND PRINTING FIELD OF THE INVENTION BACKGROUND OF THE INVENTION Printing mechanisms capable of double-printing, i.e., the simultaneous application of two characters (usually identical) to respective bands of a print-out substrate or to two bands of a single paper strip, have been described heretofore. In general the printing process for the two paper strips is performed by two separate printing blocks and start-stop elements for positioning the printing wheels as required for alignment of the selected character with a hammer or anvil associated with the individual printing block. This system has the disadvantage that a large number of start-stop elements and instruments is required, decreasing the registration and indexing accuracy and reducing the speed of the printer. The printer must also be comparatively large.

OBJECTS OF THE INVENTION SUMMARY OF THE INVENTION These objects andothers which will become apparent hereinafter are attained, in accordance with the present invention, with a printer having a print wheel with a resiliently shiftable periphery provided with two fonts of characters to be printed and having corresponding characters of these fonts located at diametrically opposite positions. A radially displaceable hammer may then drive one band of print-out material (paper strip) against the print wheel, displace the periphery thereof radially along the diameter on which the hammer is displaced, and press the print wheel against a second paper band on the opposite side of the print wheel while the paper band is supported by an anvil. In this manner the diametrically opposite characters are impressed upon the respective bands.

In other words the aforementioned objects are attained by the use of a print wheel or block of print wheels which may be surrounded by a typewriter ribbon and is flanked by two paper bands at least at diametrically opposite locations between a support or anvil and a hammer or striking mechanism at diametrically opposite locations. According to an important feature of the invention, the anvil is shiftable into and out of alignment with the hammer along a diameter of the wheel for selectively permitting and excluding the second printing.

According to another feature of the invention, the first and second feed means for advancing the first and second print-out bands between the hammer and the print wheel and between the print and the anvil, respectively, are so constructed and arranged as to orient these bands in mutually parallel stretches in planes perpendicular to the direction of the displacement of the striker or hammer. Similarly the means for guiding the pigment-carrying ribbon (typewriter ribbon) can include roller means defining at least two mutually parallel stretches of this ribbon, parallel to the planes of the paper bands and likewise perpendicularto the direction of displacement of the hammer.

According to yet another feature of the invention, a number of such printing wheels are provided on a common wheel shaft in axially adjacent relationship, each of the wheels comprising a hub mounted on the wheel shaft, a ring carried by the hub with radial play and having a flange projecting axially inwardly into an axially outwardly open groove of the h'ub,'and a rubber or other elastic annular body interposed between the ring and the hub and elastically accommodating the aforementioned radial play of the ring. The ring is formed with the aforementioned periphery provided with two fonts of characters which may be alphabetical, numerical or symbolical as desired.

The second-printing exclusion may be provided by mounting the anvil as a resilient head on a cylindrical bushing rotatable on a shaft parallel to the wheel shaft. The bushing may then have a flange at one end thereof provided with a recess engaging a banking pin for limiting angular displacement of the bushing and the pad carried thereby. A spring engaging the flange urges the pad out of alignment with the hammer across a diameter of the wheel while a pair of teeth on the flange may be respectively engaged by an electromagnetically displaceable arm or pawl to release the bushing for displacement by the spring and bya lever operated by an eccentric cam for resetting the bushing.

DESCRIPTION OF THE DRAWING The above and other objects, features and advantages of the present invention will become more readily SPECIFIC DESCRIPTION The printer according to the present invention comprises one or more resilient printing wheels 1 disposed close to one another on a common drive or wheel shaft 21 (FIG. 2), the wheel being driven by a motor or the like as represented at M. Each resilient printing wheel includes a cylindrical type-earrying ring whose rim 18 is provided with the type faces F along its periphery. The rim 18 is shiftable through a distance K in the radial direction, this distance representing the radial or diametral plane. A hub 20 carries each rim l8 and is provided with an axially open recess or groove 23 into which an inwardly extending flange or boss 22 projects to define the plane K mentioned above. interposed between the rim l8 and hub 20 is a flexible resilient element 19 in the form of a rubber body or membrane of M cross section. This body has shanks 19a and 1% respectively bonded to the hub and to the rim 18 and interconnected by a V-section web 190.

On the outer surface of the type carrying rim 18, the type characters F are arranged in two rows or fonts such that identical letters or characters are located opposite to one another and in a common center plane.

As will be apparent from FIGS. 1 and 3, the type carrying wheels 1 are surrounded in part by a typewriter ribbon (Pitman carrying ribbon) 12 which is guided along two parallel stretches 12a and 12b by the roller means 120 and 12d. The stretches 12a and 12b are generally tangent to the wheel 1 at the plane P of a striker which will be described in greater detail hereinafter. Guide means, such as a roller 10a is also provided for each of two paper bands 10 and 11 which are displaced parallel to one another and tangential to the wheel so that they too are parallel to the typewriter ribbon 12 and are perpendicular to the plane P.

The printing hammers 2 associated with each wheel I are displaceable individually by respective electromagnetic means along the plane P, i.e., along a diame ter of each wheel when the selected character is to be printed. The shaft 21 can thus be rotated continuously until the selected characters are aligned along the plane P whereupon the hammer 2 strikes in the plane P. The band 11 and the ribbon 12 passes between the hammers 2 and the type wheel 1.

An anvil arrangement, generally represented'at 9, is provided opposite the hammers along the array of type wheels. This arrangement comprises a shaft 4 parallel to the wheel shaft 21 and carrying a cylindrical bushing 3 along the periphery of which is provided a rubber pad 13 extending along a generatrix of the array of wheels. The paper band 10 and the ribbon 12 pass between the type wheel 1 and the pad 13. It will be apparent that, whenone of the hammers 2 strikes. the paper band 11 and the ribbon stretch 12b are driven against the type wheel 1 whose character D" may be juxtaposed with the hammer, thereby printing this character on the paper and likewise printing the characters of the remaining wheels having actuated hammers in a line of print. The impact of the hammers causes the type wheel to shift radially along the plane P (see the right hand wheel in FIG. 2) to drive the upper character D against the ribber stretch 12a and the paper band 10 which is supported by the pad 13. A second line of printing is provided on the second band 10. The ribbon may be displaced in the cadence of operation of the hammers by conventional means known per se.

The mechanism for excluding the second printing selectively, comprises a flange 16 connected to the right hand and of the bushing 3 (FIG. 2) and provided along its periphery with a recess of slot 24 in which a banking pin 8 is located, the latter limiting the angular displacement of the bushing and the pad 13. The flange is provided with a tooth 25 ahead of which is located an end of a bell crank lever 14 for restoring the bushing so that pad I3 is effective. The lever 14 is engaged by an eccentric cam and can assume the extreme positions illustrated in broken lines and in solid lines in FIG. 1. A further tooth 26 is provided on the flange l6 and is engageable by a pawl or arm 5 of an armature of the electromagnet 6. A spring 7 normally draws this pawl into engagement with the tooth 26 to retain the flange against clockwise movement (FIG. 1) by a spring 17 biasing the flange and the bushing in a clockwise sense.

The resilient wheels 1 rotate continuously at a given instant when the characters to be printed on each wheel are aligned at P. The hammers 2 are electromechanically actuated to print the character representation on the paper as already described. When second printing is not desired, an electrical pulse energizes the electromagnet 6 to draw the armature 5 in the counterclockwise 6 (compare FIGS. 1 and 3) to releasethe bushing 3 which is rotated by the spring 17 in the clockwise sense. The rubber pad 13 is thus shifted out of line with the plane P and does not support the paper 10 for second printing. At the conclusion of the cycle, the cam 15 swings the lever 14 in the clockwise sense to restore the bushing 3 to its operative position, whereupon the released armature 5 reaches the bushing in position shown in FIG. 1.

We claim:

1. A printer comprising:

a. a print wheel having-a resiliently shiftable periphery provided with two fonts of characters to be printed and having corresponding characters of said fonts located at diametrically opposite positions of the periphery;

b. a hammer alongside said wheel and displaceable generally along a diameter thereof to shift diametrically said periphery;

c. an anvil disposed alongside said wheel diametrically opposite said hammer;

d. first and second feed means for guiding first and second print-out bands respectively between said hammer and said periphery of said wheel and between said periphery of said wheel and said anvil for simultaneous printing of corresponding characters on both said bands upon actuation ofsaid hammer;

e. means for guiding a pigment-carrying ribbon around said periphery of said wheel and past said hammer and said anvil between the wheel periphery and said bands;

f. means for selectively shifting said anvil out of the path of a character on said periphery when the latter is displaced by said hammer for excluding printingon said second print-out band, said anvil comprising a shaft having an axis parallel to the axis of said wheel, a cylindrical bushing mounted on said shaft and rotatable about the axis thereof, a resilient pad carried by said bushing and angularly displaceable thereon into and out of alignment with said wheel along a diameter thereof through said hammer, an outwardly extending control flange formed on one end of said cylindrical bushing, a spring engaging said flange and angularly biasing said bushing to urge said pad out of diametrical alignment with said hammer across said wheel, a recess formed in said flange, a banking pin received in said recess for limiting the extent of angular displacement of said bushing, a tooth projecting from said flange, an actuating lever engageable with said tooth for angularly displacing said bushing against the force of said spring to reposition said pad in diametrical alignment with said hammer across said ringand said hub for elastically accommodating said play.

3. The printer defined in claim 1, further comprising an excentric cam bearing upon said lever for displacing same.

4. The printer defined in claim 3 wherein said flange is formed with a further tooth, said member comprising a spring biased lever forming an electromagnetically displaceable armature engageable with said further tooth.

5. The printer defined in claim 4 wherein said first and second guide means include means for passing said bands along mutually parallel stretches past said wheel, said means for guiding said pigment-carrying ribbon around said periphery of said wheel including rollers forming a transport path having mutually parallel stretches running along said stretches of said bands, said hammer being displaceable perpendicularly to said stretches.

6. The printer defined in claim ll, further comprising:

g. a wheel shaft carrying said wheel, said wheel comprising a hub mounted on said wheel shaft and angularly displaceable therewith, a ring surrounding said hub and radially shiftable relative thereto, said hub being formed with an axially open annular recess turned in one direction, said ring forming said periphery and being provided along its rim with said characters, a flange formed on said ring and lying along a flank of said hub while having an axially inwardly turned portion received in said groove, and an elastic annulus interposed between said ring and said hub for limiting the radial displacement of said ring. 

1. A printer comprising: a. a print wheel having a resiliently shiftable periphery provided with two fonts of characters to be printed and having corresponding characters of said fonts located at diametrically opposite positions of the periphery; b. a hammer alongside said wheel and displaceable generally along a diameter thereof to shift diametrically said periphery; c. an anvil disposed alongside said wheel diametrically opposite said hammer; d. first and second feed means for guiding first and second print-out bands respectively between said hammer and said periphery of said wheel and between said periphery of said wheel and said anvil for simultaneous printing of corresponding characters on both said bands upon actuation of said hammer; e. means for guiding a pigment-carrying ribbon around said periphery of said wheel and past said hammer and said anvil between the wheel periphery and said bands; f. means for selectively shifting said anvil out of the path of a character on said periphery when the latter is displaced by said hammer for excluding printing on said second print-out band, said anvil comprising a shaft having an axis parallel to the axis of said wheel, a cylindrical bushing mounted on said shaft and rotatable about the axis thereof, a resilient pad carried by said bushing and angularly displaceable thereon into and out of alignment with said wheel along a diameter thereof through said hammer, an outwardly extending control flange formed on one end of said cylindrical bushing, a spring engaging said flange and angularly biasing said bushing to urge said pad out of diametrical alignment with said hammer across said wheel, a recess formed in said flange, a banking pin received in said recess for limiting the extent of angular displacement of said bushing, a tooth projecting from said flange, an actuating lever engageable with said tooth for angularly displacing said bushing against the force of said spring to reposition said pad in diametrical alignment with said hammer across said wheel, and an electromagnetically displaceable hammer engageable with said flange and energizable to release same for displacement by said spring.
 2. The printer defined in claim 1 wherein said wheel comprises a hub having an annular groove, a ring mounted on said hub with radial play and having an inwardly extending flange projecting into said groove, said ring being formed with a type carrying rim provided with said characters and forming said periphery, and an annular resilient body interposed between said ring and said hub for elastically accommodating said play.
 3. The printer defined in claim 1, further comprising an excentric cam bearing upon said lever for displacing same.
 4. The printer defined in claim 3 wherein said flange is formed with a further tooth, said member comprising a spring biased lever forming an electromagnetically displaceable armature engageable with said further tooth.
 5. The printer defined in claim 4 wherein said first and second guide means include means for passing said bands along mutually parallel stretches past said wheel, said means for guiding said pigment-carrying ribbon around said periphery of said wheel including rollers forming a transport path having mutually parallel stretches running along said stretches of said bands, said hammer being displaceable perpendicularly to said stretches.
 6. The printer defined in claim 1, further comprising: g. a wheel shaft carrying said wheel, said wheel comprising a hub mounted on said wheel shaft and angularly displaceable therewith, a ring surrounding said hub and radially shiftable relative thereto, said hub being formed with an axially open annular recess turned in one direction, said ring forming said periphery and being provided along its Rim with said characters, a flange formed on said ring and lying along a flank of said hub while having an axially inwardly turned portion received in said groove, and an elastic annulus interposed between said ring and said hub for limiting the radial displacement of said ring. 